1. Field of the Invention
The present invention relates to a recording tape cartridge which rotatably accommodates a single reel onto which a recording tape such as a magnetic tape or the like is wound.
2. Description of the Related Art
Recording tapes such as magnetic tapes and the like are used as external recording media for computers and the like. Recording tape cartridges that accommodate a single reel on which a recording tape is wound take up little space when stored and can record large amounts of information, and are employed as such recording tapes.
An opening aperture is formed in a case of such a recording tape cartridge. The recording tape is drawn out through this opening, and wound around a drive device side winding reel. Accordingly, there have been various schemes in the prior art for preventing dust and the like from ingressing through the opening aperture and adhering to the recording tape.
In a recording tape cartridge 100 shown in FIG. 7, an opening 104 is formed in a side wall 102A of a case 102 (a side wall along a case loading direction A). This opening 104 is structured to be openable and closeable by a door 106 which slides along the loading direction (for examples, refer to Japanese Patent Application Laid-Open (JP-A) Nos. 11-297032, 11-213615, 11-242871 and 2000-331403).
However, with this position of the opening aperture 104, it is necessary that a drive device side operation member turns a leader pin 108 around from a direction sideward of the case 102 when drawing out the leader pin 108. The leader pin 108 is a leader member attached at an end portion of a magnetic tape T, which is the recording tape. Therefore, a space for this turning around by the operation member must be conserved at the drive device. Moreover, a structure for the turning around by the operation member is complicated, and inevitably leads to an increase in size of the drive device. In addition, another aspect to be considered is that a drawing-out path of the magnetic tape T to a winding reel 110 becomes long.
Alternatively, in a recording tape cartridge 112 shown in FIG. 8, an opening 116 is formed in a front face wall 114A of a case 114 (a forward wall which faces in case loading direction A). This opening 116 is structured to be openable and closeable by a swivel-type door 118, which opens and closes by rotation about a shaft (for examples, refer to JP-A 9-039832 and the specification of U.S. Pat. No. 5,332,173).
In this recording tape cartridge 112, because the opening 116 is formed in the front face wall 114A, there is no requirement for a drive device side operation member to turn the leader member around from a sideward direction when drawing out a magnetic tape T. However, the door 118 opens outward by a large amount. Therefore, it is necessary to conserve space at the drive device side such that opening and closing operations of the door 118 are not impeded. As a result, the drive device becomes larger.
Further, in a recording tape cartridge 120 shown in FIG. 9, an opening 124 is formed by cutting away a corner portion of a case 122. The opening 124 is structured to be opened and closed directly by a leader block 126, which is a leader member connected to an end portion of a magnetic tape T (for examples, refer to Japanese Patent Application Publication (JP-B) Nos. 61-61470 and 63-53633).
If the leader block 126 functioned only as a door for closing the opening 124, then the occurrence of damage, soiling or the like at the leader block 126 would not be a problem. However, the leader block 126 is a structure which is drawn out as is by an operation member and fitted into a hub 130 of a drive device side winding reel 128. Therefore, when damage or soiling occurs at the leader block 126, the leader block 126 may not fit well with the hub 130, and this may have a deleterious effect on running of the magnetic tape T. Moreover, the leader block 126 structures a portion of a winding surface onto which the magnetic tape T is wound. Therefore, there is a risk that, as a result of the aforementioned damage or soiling, data recorded on the magnetic tape T may be damaged or an unrecordable region may be caused at the magnetic tape T.
In addition, the leader block 126 is anchored only at peripheral portions of the opening 124. Therefore, there is a risk that the leader block 126 may fall out if the case 122 is dropped. Moreover, because the leader block 126 is larger in size than a leader pin, there are many more constraints on the form of the case 122.